Tumblr is supporting Spirit Day on its own social media channels, as well. The idea for Spirit Day was first posted to Tumblr by Canadian teen Brittany McMillan in 2010, and the company observed the first Spirit Day in 2010 by turning its logo purple. This year, the staff recorded a video with Spirit Day Ambassador Brittany McMillan, which it posted on the Storyboard blog. Tumblr also plans to promote Spirit Day with more editorial content, and staff also plans to wear purple on October 19! Check out Tumblr's video with Brittany below:

On Spirit Day, StumbleUpon will turn its logo purple across its social media platforms, include Facebook, Instagram, Twitter. The staff also plans to tweet about #SpiritDay and encourage employees to wear purple. StumbleUpon will also center the themes of posts around purple for the day.

Hulu has also announced its support for Spirit Day. The company plans to talk about Spirit Day on its social media channels on Friday.

Mobli is participating by creating a special Spirit Day channel where users can share photos of themselves wearing purple to stand up against bullying.

"When young people find a sea of purple profile photos and supportive voices on their favorite websites and apps, it sends a powerful message that it's okay to be who you are," said GLAAD president Herndon Graddick. "Tech giants like Facebook and Yahoo! are leading the way in taking steps to address bullying and bringing Spirit Day's message to young people year round."

Social media is critically important to spreading the word about Spirit Day, and supporters are encouraged to make their Facebook and Twitter profile photos purple using the tools on the Spirit Day website, www.glaad.org/spiritday. GLAAD also provides graphics that can be shared on social media sites.

GLAAD introduced two Spirit Day mobile apps powered by Toyota Financial Services which can be downloaded from the Apple App Store and Google Play. Download them today to turn your photos purple and add a special #SpiritDay badge that is only available by using the mobile apps.

Other tech companies supporting Spirit Day this year include Comcast, Yahoo!, Mobli and AT&T. See all participants and get involved at www.glaad.org/spiritday!

If your tech company, start up, or social media firm would like to sign on as a Spirit Day participant, it's not too late to sign up.